1. Field of the Invention
The present invention relates in general to swash plate type compressors employed in an automotive air conditioning system, and more particularly to the swash plate type compressors of a type having a pulsation damping structure.
2. Description of the Related Art
In order to clarify the task of the present invention, a known swash plate type compressor will be briefly described with reference to FIGS. 16 and 17 of the accompanying drawings.
In FIG. 16, there is shown the known swash plate type compressor for use in an automotive air conditioner system, which comprises a cylinder block 2 in which a rotation shaft 10 is rotatably held. A rear head 6 is attached to a rear end of the cylinder block 2 through a valve plate 9. A swash plate 15 is pivotally held on the rotation shaft 10 through a holder arm 15a fixed to the rotation shaft 10. Designated by numeral 5 is a crank chamber defined in the cylinder block 2. Six cylindrical piston bores 3 are circumferentially arranged around the right end of the rotation shaft 10, each having a piston 18 axially slidably received therein. Each piston 18 has a holding portion that slidably holds a peripheral portion of the swash plate 15. Thus, when, with the swash plate 15 kept inclined relative to the rotation shaft 10 as shown, the rotation shaft 10 is rotated about its axis, the swash plate 15 rotates therewith thereby to pull and push (viz., reciprocate) the pistons 18 in the associated piston bores 3 one after another. Due to the reciprocating movement of each piston 18, a refrigerant gas is led into each piston bore 3 from a refrigerant intake chamber 7 through an inlet opening 3A, compressed in the piston bore 3 and then discharged to a refrigerant discharge chamber 8 through an outlet opening 3B. The outlet opening 3B is equipped with a valve plate 3b that permits only a discharge flow of the refrigerant from the piston bore 8 to the discharge chamber 8. The inlet and outlet openings 3A and 3B are formed in the valve plate 9, as shown. The refrigerant intake and discharge chambers 7 and 8 are defined by a generally annular partition wall 11 formed in an inner side of the rear head 6. That is, the refrigerant intake chamber 7 extends circumferentially around the annular partition wall 11. As is seen from FIG. 17, the refrigerant intake chamber 7 is connected with a refrigerant intake port 12, and the refrigerant discharge chamber 8 is connected with a refrigerant discharge port (not shown).
When the rotation shaft 10 is rotated about its axis and thus the pistons 18 are forced to reciprocate in the corresponding piston bores 3, a refrigerant gas from an evaporator (not shown) is led into the refrigerant intake chamber 7 through the refrigerant intake port 12, and led into the piston bores 3 and compressed one after another by the corresponding pistons 18. The compressed refrigerant is then led to the refrigerant discharge chamber 8 through the respective outlet openings 3B and led to a condenser (not shown).
However, due to inherent construction of the above-mentioned compressor, under operation, a certain pressure difference tends to occur between a position near the refrigerant intake port 12 (see FIG. 17) and a position remote from the intake port 12. It has been revealed that such pressure difference is caused by a pressure loss inevitably produced when the refrigerant gas flows from the intake port 12 toward the inside of the refrigerant intake chamber 7. However, when, under appearance of such pressure difference, the refrigerant gas is led into the piston bores 3 through the inlet openings 3A, the flow of the refrigerant gas tends to produce undesirable pulsation in accordance with the pressure difference and/or the unevenness of the pressure in the refrigerant intake chamber 7. In addition to this, since the rear head 6 is commonly equipped with both a flow control valve (not shown) for the refrigerant gas and an actuating mechanism (not shown) for the flow control valve, the refrigerant intake chamber 7 is compelled to have a complicated shape, which promotes creation of the undesired pressure difference in the chamber 7.
The above-mentioned undesirable phenomenon may be much clarified from the following description with the aid of FIG. 17. That is, under operation of the compressor 6, the pressure at the portion B1 for a first piston bore 3 is kept higher than that at the portion B2 and/or B3, which causes the pressure difference in the intake chamber 7 and thus generation of pulsation of the refrigerant gas flow. As is known, such pulsation causes generation of vibration and/or noises of the compressor. Although enlargement of the refrigerant intake chamber 7 may reduce or dampen the pressure difference, the same causes enlargement of the entire construction of the compressor.
Accordingly, an object of the present invention is to provide a swash plate type compressor which is free of the above-mentioned drawbacks.
That is, according to the present invention, there is provided a swash plate type compressor which can dampen the undesirable pulsation of a refrigerant flow thereinto irrespective of its simple and compact construction.
According to a first aspect of the present invention, there is provided a compressor which comprises a cylinder block; compressing means installed in the cylinder block to compress a refrigerant gas led thereinto; a valve plate connected to a rear end of the cylinder block, the valve plate having a group of inlet openings which are connected to the compressing means to introduce a refrigerant gas into the compressing means and another group of outlet openings which are connected to the compressing means to discharge the refrigerant gas thus compressed from the compressing means; a rear head connected to the valve plate, the rear head having an intake chamber exposed to the inlet openings and a discharge chamber exposed to the outlet openings, the intake chamber surrounding the charge chamber, the rear head having an intake port connected to the annular intake chamber and a discharge port connected to the circular discharge chamber; and a baffle plate installed in the intake chamber to obstruct a direct flow of the refrigerant gas from the intake port to the inlet openings.
According to a second aspect of the present invention, there is provided a swash plate type compressor which comprises a cylinder block; a rotation shaft rotatably held in the cylinder block; a swash plate swingably connected to the rotation shaft to rotate therewith; a plurality of piston bores circumferentially arranged about the rotation shaft; a plurality of pistons operatively received in the piston bores respectively, each piston having a holding portion that slidably holds a peripheral portion of the swash plate, so that when the rotation shaft is rotated about its axis, the swash plate pulls and pushes the pistons thereby to reciprocate the same; a valve plate connected to a rear end of the cylinder block, the valve plate having a group of inlet openings connected to the piston bores respectively and another group of outlet openings connected to the piston bores respectively; a rear head connected to the valve plate, the rear head having an intake chamber exposed to the inlet openings and a discharge chamber exposed to the outlet openings, the intake chamber surrounding the discharge chamber, the rear head having an intake port connected to the intake chamber and a discharge port connected to the discharge chamber; and a baffle plate installed in the annular intake chamber to obstruct a direct flow of a refrigerant gas from the intake port to the inlet openings.
According to a third aspect of the present invention, there is provided a compressor which comprises a cylinder block; compressing means installed in the cylinder block to compress a refrigerant gas led thereinto; a valve plate connected to a rear end of the cylinder block, the valve plate having a group of inlet openings connected to the piston bores respectively and another group of outlet openings connected to the piston bores respectively, each outlet opening having a valve plate that permits only a discharge flow of the refrigerant gas from the piston bore; a rear head connected to the valve plate, the rear head having a generally annular intake chamber exposed to the inlet openings and a generally circular discharge chamber exposed to the outlet openings, the rear head having an intake port connected to the annular intake chamber and a discharge port connected to the circular discharge chamber; and an arcuate baffle plate installed in the generally annular intake chamber in a manner to obstruct a direct flow the refrigerant gas from the intake port to a given group of the inlet openings.
According to a fourth aspect of the present invention, there is provided a swash plate type compressor which comprises a cylinder block; a rotation shaft rotatably held in the cylinder block; a swash plate swingably connected to the rotation shaft to rotate therewith; a plurality of piston bores defined in the cylinder block and circumferentially arranged about the rotation shaft; a plurality of pistons operatively received in the piston bores respectively, each piston having a holding portion that slidably holds a peripheral portion of the swash plate, so that when the rotation plate is rotated about its axis, the swash plate pulls and pushes the pistons thereby to reciprocate the same; a valve plate connected to a rear end of the cylinder block, the valve plate having a group of inlet openings connected to the piston bores respectively and another group of outlet openings connected to the piston bores respectively, each outlet opening having a valve plate that permits only a discharge flow of a refrigerant gas from the piston bore; a rear head connected to the valve plate, the rear head having a generally annular intake chamber exposed to the inlet openings and a generally circular discharge chamber exposed to the outlet openings, the rear head having an intake port connected to the annular intake chamber and a discharge port connected to the circular discharge chamber; and an arcuate baffle plate installed in the generally annular intake chamber in a manner to obstruct a direct flow the refrigerant gas from the intake port to a given group of the inlet openings.